PROVIDENCE, R.I. — Rep. Patrick Kennedy, who has struggled with depression, alcoholism and addiction for much of his life, said Friday that he has checked into a medical facility for treatment.

The Rhode Island Democrat, who sought treatment three years ago after an early-morning car crash near the U.S. Capitol, said in a statement that his recovery is a “lifelong process” and that he will do whatever it takes to preserve his health.

“I have decided to temporarily step away from my normal routine to ensure that I am being as vigilant as possible in my recovery,” said Kennedy, the son of Sen. Edward Kennedy, D-Mass. He did not say exactly what he was being treated for, and did not disclose the facility’s location.

Kennedy, who has wrestled with alcoholism, bipolar disorder and an addiction to prescription drugs, has often spoken publicly about his recovery and the importance of removing any stigma associated with mental illnesses.

He has been a leading voice in Congress on mental health issues, championing legislation to require insurance companies to treat mental health on an equal basis with physical illnesses, when policies cover both.

The measure passed last October as part of a $700 billion financial bailout.

“I hope that in some small way my decision to be proactive and public in my efforts to remain healthy can help remove the stigma that has served as a barrier for many Americans reluctant to get the help they needed,” he said.

Kennedy’s office declined to offer any details about the congressman’s health or what prompted him to seek treatment. He sought the treatment in the last few days, his office said.

“He takes his health very seriously and had conversations with his doctors, and they thought it was best for him to step away from his work right now and go in and get some medical care,” said Jack McConnell, a lawyer, longtime Kennedy friend and former campaign manager.

“I’m incredibly proud of him for doing it,” he added.

He said no particular incident or relapse prompted his decision to seek treatment.

In May 2006, Kennedy crashed his 1997 Ford Mustang into a security barrier on Capitol Hill in the early morning hours. He entered into a rehabilitation program at the Mayo Clinic in Minnesota. He agreed to a plea deal on a charge of driving under the influence of prescription drugs and received a year’s probation.

He later revealed that he sought treatment for an addiction to the painkiller OxyContin months before the crash.

Kennedy also said he went to rehab as a teenager for an addiction to cocaine, and has since said he was in recovery for depression and alcoholism. In 2000, he was accused of shoving an airport security guard in Los Angeles and trashing a yacht.

“I think most people understand that addiction is a disease, and it’s a fatal disease if we don’t deal with it,” said former Rep. Jim Ramstad of Minnesota, a recovering alcoholic who has sponsored Kennedy in Alcoholics Anonymous.

“People like Patrick and me need to deal with our recovery one day at a time, for the rest of our lives.”

Kennedy continues to enjoy high popularity ratings in Rhode Island, cruising to an eighth term in last November’s elections.

Giovanni Cicione, chairman of the state Republican Party, said he was glad Kennedy was treating his illness, but added, “At some point, we’ve got to say when is enough enough?”